Application Of GPR Image Analysis Technique To Hydraulic Concrete Structure Detection

By using the propagation of electromagnetic (EM) wave in medium and recording its transmitting time, the intensity of EM field and its wave shape, Ground Penetrating Radar (GPR) can be used to detect the structure properties of buried objects. Due to its characteristics of convenience, rapidness and non-destruction, GPR has become one of the most widely used geophysical exploration methods.Data processing and explanation for GPR images is a very important procedure. On the one hand, different data processing procedures and parameters should be chosen based on the properties and shape of the buried objects; on the other hand, detailed analyses on the image characteristics derived from other detecting methods should be carried out. Then, clear images can be obtained and consequently explained reasonably. However, the experience was mainly limited to qualitative analysis in the past, and little could be used in quantitative analysis. In order to solve this problem, a series of abbreviated Matlab programs are presented in this paper. These programs can simulate the GPR image by forward simulation theory, and consequently explain the GPR image quantitatively.In the dissertation, some principles about EM wave were introduced firstly. Then according to the theory of GPR, how to properly employ GPR under different environment and conditions was discussed. After that, in terms of the rules of EM wave transmission in media, Matlab programs were used to simulate various display modes of GPR image, and consequently the general rules of three modes of GPR image were revealed. Hence, we draw a conclusion that GPR images could be explain by forward simulation analysis. In the last chapter of the paper, the effectiveness of various display modes by forward simulation was verified by experiments and project applications.